Sound-box for talking-machines.



M. KEEN.

scum) Box FOR TALKING MAGHINES.

APPLICATION FILED JULYYQ, 1909.

940, 1 61 Patented Nov. 16, 1909.

' TIESSES diaphragm is yieldingly supported in the.

UNITED STATES" PATENT orruon.

monnrs xnnimior PHILADELPHIA,'TENNSYLVANIA.

SOUND-BOX FOR TALKING-MACHINES.

Specification of Letters Patent. Patented Nov. 16, 1909.

Application filed July 9, 1909. Serial No. 506,664.

To all it mag concern:

Be it known that I, MORRIS KEEN, a citizen of the United States, and a resident of the city and county of Philadelphia and box so that it has capacity for vibration adjaeent to its perimeter as well as at its center and to otherwise construct the sound box as a whole that it will be inexpensive to construct, sensitive in action and easily and v hereinafter and morev quickly repaired.

-My invention consists of certain features of construction whichare fully described particularly defined in the claims.

The invention will be better understood by reference to the drawings, in which:

Figure I is an elevation of a sound box embodying my invention; Fig. 2 .is a cross the ox.

outside and upon which' serewed a cap b,

sectional view of the same Fig. 3 is an enlarged 'cross section of a portion of the same; Fig. 4 is a plan view of the clamping the ielding lining be rebeing' applied to a is the body ofthe boxand i'sfmade 'circular with an annular back g.- The open end of this box a is screw-threaded upon the the inner annular 1 flange. 'cj 50f which cooperates with therannularrim'yof the box to clamp a yielding lining efl The yielding lining e may be of rubber, felt or other textile or elastic material and having an annular shape indicated in Fig. 5 before being applied within the box. When applied in position within the box, the outer perimeter of this lining is first clamped between the flange c and 'the-rimof thebody a. A

washer or annular ring isthen placed over the. middle. partvof the lining and pressed downwardinto the box with its central aperture in line with the a erture in the middle of. the back g of the ox. A rear tubular v annular plate; and Fig. 5is.a plan view of part it having the screw-threaded shank i.

is then placed in positiorrat the back of the box with the tubular screw-threaded end z' extending through the aperture thereof and screwed into the aperture in the washer or annular ring 7. By turning the tubular part '72. upon the sound box body the clamping washer or ring 1 is drawn toward the back 9 until it tightly clamps the yielding lining will then be stretched from the clamping cap 1) down to the clamping washer or ring f and forms a conical, lining to the body. A diaphragm lcofmetal or other suitable, material, having a diameter slightly less thanthe inner diameter of the body a, is pressed downward into the yielding lining a and is held in position parallel to the backof the box and the washer or clampingv ring f thereof.

To give to the diaphragm a desirable yielding support about its perimeter, I provide a deep and wide annular groove d on the inner face ofthe body a and imme--.

diately'in line with the diaphragm so that the yielding lining is stretched over the edge of the diaphragm and is supported by the body a oneach side of'the annular groove 03'.

As the yielding lining is free to move in all directions adjacent to the perimeter of the diaphragm it will be understood that in vibrating' the diaphragm, not only will the lining e, as indicated in Figs. 2 and'3. The

center be vibrated, bu-t the perimeter'o'f' the.

diaphragm will also havemoreorlessufree vibration in a direction at a right angle 1:0'

the plane of the diaphragm. The diaphragm is, in eifect, a floating diaphragm free to. be

moved bodily by the stylus bar. The yield= ing, lining e is supported tightly against the inner face of the-body between the annular groove d andthe flange c of the clamping cap 6 and from'the groove downward it is preferably clear of, the inner-' wall of the body. By examining Fig. 3,'it will be seen that the diaphragm is normally held in a yielding manner bythe flexible lining and while no great strain is put upon the diaphrag-ni to interfere with its movement in any directiom there is nopossib'ility of escape of airaround the perimeter of the diaphragm. p

7' is a stylus bar and has one end secured to the center of the diaphragm -70 and the other-end provided with a clamp 0 for .receiving and holding the stylus orneedle point. The stylus bar 7' is pivoted to the cap I) at. m and a so that it is free to oscillate upon an axis a rranged parallel to the plane of the diaphragm. To provide room for the adjustment springs, I prefer to form the stylus I bar cross shaped, as indicated in Fig. 1. The cross piece Z of the stylus bar is provided with large holes through which the adjusting screws 7) extend and said screws are screwed into the cap b,'as clearly'indicated in Figs. 1 and 2. Between the heads of the screw and the cross piece Z of the stylus bar, I provide coil springs which press upon the stylus bar structure to hold it in a normally intermediate position and with provisions for adjustment to make it more or less sensitive to being oscillated and by which to regulate the degree of vibration permitted to the diaphragm.

Other ways of supporting the stylus bar may be en'iployed in place of that shown, as

my improved manner of holding the dia-- phragm maybe employed with any mechanism for supporting the stylus bar which will permit freedom of vibration of the diaphragm.

While I prefer in practice, to employ rubher for the lining c, as .l have found this best suited for the purpose; I may nevertheless employ felt, flannel or other textile material having yielding properties, it so desired.

Other means of holding the clamping washer f may be employed in lieu of those shown; and in general, while I prefer the construction illustrated, I do not restrict myself to the minor details thereof, as these may be modified without departing from the spirit of the invention.

I Having now described my invention, what I claim as new and desire to secure by Letters Patent, is: v

1. In a sound box, a body part having a circular interior provided with an annularly grooved wall, combined with a yielding lining secured to the body at its front part and extending inwardly over the annular groove and secured adjactmt to the back of the body,

diaphragm yieldingly supported by the yielding lining adjacent to and in the plane of the annulargroove, and a stylus bar having a connection with the diaphragm. Y

2. In a sound box,'a body part having a circular intcriorp rovided with an annnlarly grooved wall, combined with a yielding lining secured to the body at 1ts front part and extending inwardly over the annular groove and secured adjacent to the back of the body by a clamping ring within the body for clamping the middle part of the yielding lining adjacent to the back of the body, means to hold the clamping r1ng 1n POSI- tion upon the back, a diaphragm yieldingly supported by the yielding lining adjacent to and in the plane of the annular groove, and a stylus bar having a connection with the diaphragm.

3. In a sound box, a body part having a I circular interiorprovided with an annularly grooved wall, combined with a yielding lin ing secured to the body at its front part and extending inwardly over the annular groove and secured adjacent to the back of the body by a clamping ring within the body for clamping the middle part of the yielding lining adjacent to the back of the body, means to hold the clamping ring in position upon the back consisting of a tubular part resting against the b ack and having a screwthreaded end extending through the back and engaging the clamping ring, a diaphragm yieldingly supported by the yielding lining adjacent to and in the plane of the annular groove, and a stylus barhaving a connection with. the diaphragm.

hln a's'ound box, a body part having a 5. In aso'ud box, the combination of acircular body havin its inner wall provided with a deep annular groove, a clamp ing cap adapted to the outer rim of the -u' 1' interior provided with an annularly vied wall, combined with a yielding l1n-' body, an annular lining of yielding material 1 clamped between the rim of the body and the cap, means within the body for clamping the inner part of the yielding lining at a point within the body, a diaphragm .within the body and engaging the yielding lining in the plane of the,deep annular groove, and a stylus bar connected with the diaphragm.

6. In a sound box, the combination of a circular body having its inner Wall provided with a deep annular groove, a clamping cap adapted to. the outer rim of the body, an

annular lining of yieldin material clamped between the rim of the body and the cap, means within the'body for clamping the inner part of the yielding lining at a point within the body consisting of an annular clamping plate, a screw-threaded tubular part extending through the back of the body and engaging the annular clamping plate,'a diaphragm within the body and engaging the yielding lining-in the plane of the deep annular groove, and a stylus bar connected with the diaphragm.

' 7. In a sound box, the combination of a.

metallic box having a circular interior, a.

lining of yielding material forming a circular. yielding wall within the box unsupported in a plane between its outer and inner edges,

a diaphragm having its erimeter pressed into contact with the yie ding lining at a place corresponding to the plane vthereof In testimony of which invention, I here unto set my hand.

MORRIS KEEN.

which is unsupported whereby the diaphragm is yieldingly supported by the lin- Witnesses:

ing, and a stylus bar having a connection R. M. HUNTER, with the body for vibrating the diaphragm. R. M. KELLY. 

